The invention relates to a method for mounting an integral inner ring of a turbocompressor stator to a guide vane ring.
In turbocompressors for gas turbines that have a stator with vanes, the guide vanes are mounted on a torsionally rigid inner ring. The inner ring is provided with openings (bearing depressions), into which the bearing bushes for the inner pins of the guide vanes can be inserted. The installation (mounting) of the inner ring is produced only when the guide vanes are inserted in the compressor housing. In the case of inner rings without axial partition, mounting has previously been possible only segmentally. The inner ring is divided into individual segments in the peripheral direction with a center angle of <180°, and the segments with the openings are individually “threaded” with the inner pins of the guide vanes, as long as the gap between the segments permits this. In practice, the segments thus usually have a center angle that is not greater than 30°.
Such a segmented inner ring is shown, for example, in EP 1 508 672 A1. A method for mounting a segmented inner ring without axial partition is known from DE 10 2006 024 085 A1. In the method described therein, the fact is exploited that the openings in the segments of the inner ring are clearly larger in diameter than the inner pins of the guide vanes, so that the latter can be positioned temporarily eccentrically and obliquely in the openings.
However, in comparison to one-part, closed (integral) inner rings, segmented inner rings have basic disadvantages. Thus, segmenting leads to a greater wear and a considerably shortened service life. Segmenting also leads to an undesired cluster vibrating.